<div class="context">
  选择:第{{ data.studentChoice.titleNumber }}题
  <mat-radio-group class="radio-group" (change)="getChoice($event)">
    <mat-radio-button class="radio" value="A" [checked]="isCheck_A">
      {{ data.choice[0] }}
    </mat-radio-button>
    <mat-radio-button class="radio" value="B" [checked]="isCheck_B">
      {{ data.choice[1] }}
    </mat-radio-button>
    <mat-radio-button class="radio" value="C" [checked]="isCheck_C">
      {{ data.choice[2] }}
    </mat-radio-button>
    <mat-radio-button class="radio" value="D" [checked]="isCheck_D">
      {{ data.choice[3] }}
    </mat-radio-button>
  </mat-radio-group>
</div>
